GB1030285A - Coating composition - Google Patents

Abstract

In the coating compositions for metal and other surfaces as disclosed in the parent Specification and containing (1) a dissolved phosphate (2) dissolved chromates dichromates or molybdates and (3) a metal ion, the proportions of the mixture are of (1) 1 to 4 mols per litre of solution, (2) .5 to 3 mols, and (3) 1 to 4 mols, and a particulate solid is added preferably smaller than 100 mesh e.g. powdered in soluble metals, graphite, MoS2, MoSi, metal carbides, silicides, nitrides, silica, Al2O3, WS, lead oxide, ZnO2; as metal powders. Al, Cu, Ag, OO Ni are used. The coating is dried and stoved at 500 DEG to 1000 DEG F. which bonds the coating to the surface, and renders it insoluble. Surfaces treated include sheet steel, and ceramics. The dissolved phosphate may be H3Po4 on phosphates of metals forming the metal ion component (3) e.g. mono-phosphates of Mg, Zn, Ca, and Li. The chromate may be CrO3 itself, or as a chromate, and similarly MoO3 and molybdates. In examples, MgO is dissolved in H3Po4, to which is added Mg di-phosphate, and chromate in the specified proportions. To the solution is then added powder Al of size 5 to 10 m , to form a slurry. This is applied to sheet steel by spraying, dipping or rolling, and cured at 625 DEG F., forming a flexible abrasion-resistant coating. Other examples of ingredients are, (1) CrO3, H3Po4, MgO, (2) CrO3, H3Po4, LiOH, (3) MgCr2O7, Fe3(Po4)2, H3Po4, each of which is a solution in water, to which silica, Mo silicide, or a mixture of lead oxide and graphite is added to form a slurry. Several coatings may be applied with or without intermediate curing.ALSO:In the coating compositions for ceramic surfaces as disclosed in the parent Specification and containing (1) a dissolved phosphate, (2) dissolved chromates, dichromates, or molybdates and (3) a metal ion, the proportions of the mixture are of (1) 1 to 4 mols. per litre of solution (2) .5 to 3 mols, and (3) 1 to 4 mols, and a particulate solid is added, preferably smaller than 100 mesh e.g. powdered insoluble metals, graphite, Al2O3, MoS2, MoSi, metal carbides, silicides, and nitrides; silica, WS, lead oxide, ZrO2; as metal powders Al, Cu, Ag, or Ni are used. The coating is dried and stored at 500 DEG to 1000 DEG F., which bonds the coating to the surface and renders it insoluble. The dissolved phosphate may be H3Po4 or phosphates of metals also forming the metal ion component (3) e.g. mono-phosphates of Mg, Zn, Ca and Li. The chromate may be CrO3 itself or a chromate, and similarly MO3 and molybdates. In examples, MgO is dissolved in H3Po4 to which is added Mg diphosphate and chromate all in the specified proportions. To the solution is then added powdered Al of size 5 to 10m , to form a slurry. This is applied to a surface by spraying, dripping or rolling, and cured at 625 DEG F., forming an abrasion-resistant coating. Other examples of ingredients are, (1) CrO3, H3 Po4, MgO (2) CrO3, H3 Po4, LiOH, (3) MgCr2O7, Fe3(Po4)2, H3Po4, each of which is a solution in water, to which is added silica, MoSi, or a mixture of lead oxide and graphite to form a slurry. Several coatings may be applied with or without intermediate curing.